Reenforcement of high speed abrasive wheels



Dec. 4; 1934.

F. J. TONE REENFOHCEMENT OF HIGH SPEED ABRASIVE WHEELS Filed May '25,1929 INVENTOR FRANK J. Tom:

ATTORNEY for abrasive wheels;

Patented Dec. 4, 1934 REENFORCEMEN T OF-HIGH SPEED ABRASIVE WHEELS FrankJ. Tone, Niagara Falls, 'N.

Y., assignor to The Carborundum Company, Niagara Falls, N. Y., acorporation of Pennsylvania Application May 25, 1929, Serial No. 366,034

8 Claims. (Cl. 51-206) This invention relates to the lateralreenforcement of abrasive wheels and particularly to lat: eralreenforcements in which the reenforcement can be worn away automaticallyduring the grinding process or may be easily removed bythe occasionalapplication of a tool while the wheel is in operation. Another type ofreenforcement for abrasive Wheels has been described in 00- pending U.S. application Serial No. 313,087, filed October 17, 1928, and also inco-pending application Serial No. 336,557, filed January 31, 1929 (thesetwo applications 313,087 and 336,557 have been replaced by Serial No.445,367 filed April 18, 1930). The present application differs fromthese c'o-pending applications principally in the method of applying thelateral reenforcements to the wheels and in the manner of removal of thesaid reenforcements.

Lateral reenforcements are intended particularly for wheels which areused at speedsgreater than the usual peripheral speeds of 5500 to 6500feet per minute, as for example, 9000 feet per minute. It has been foundthat the diameter of a rapidly revolving abrasive wheel becomes greaterthan the diameter of that same wheel at rest. This actual increase indiameter is due to centrifugal force and is consequently a function ofthe square of the linear velocity of the wheel for a given radius.

If the centrifugal force set up in the revolving wheel is great enoughto strain the abrasive material beyond its elastic limit, it is almostcertain to cause the wheel to burst, because the elastic limit and pointof failure are very close in abrasive materials, particularly in thecase of vitrifled articles.

As in the case of the co-pending applications referred to, an abrasivewheel to be-protected is provided with lateral reenforcements, which isI accomplished by applying to one or both faces of the wheel, areenforcement which elongates much less under a stress than the abrasivewheel does under the same stress. The latter of the above mentionedco-pending applications describes a method of reenforcement of abrasivewheels by cementing metal strengthening members to each side of thewheel by means of a cement of such thickness and characteristics thattogether with the metal it forms a substantial reenforcing member whichprevents the increase in the diameter of the wheel beyond the elasticlimit of the wheel under ordinary use.

I have, so far, described the desirable features which are the object oflateral reenforcements In considering the type of lateral reenforcementwhich is to be used in the particular case, such matters as the ease ofapplication of the reenforcement and the ease with which it can beremoved should be considered. In the case of metal rings'or disks it isnecessary to center the reenforcementswith considerable care. There are,also, certain difiiculties in removing such reenforcements, 'forexample, the actual use of the wheel must be interrupted and a period ofthree to ten minutes taken to remove the unnecessary outer portionsofth'e reenforcement. The invention described below provides means toeliminate the interruption of the operation of the wheel and the loss oftime in removing reenforcements.

'I have invented the following methods which I believe are characterizedparticularly by the ease by which the reenforcements may be applied andremoved respectively.

These methods are illustrated by the accompanying drawing in which:

Figure 1 represents a side view of an abrasive wheel which has beenreenforced by the application ofa spray of liquid metal at highpressure; and v v Figure 2 is a section of Fig. 1 taken on the line 2-2.

The process referred to will be considered in detail. In applying metalreenforcements by my method I may use spraying or electrodeposition orcombinations of these processes. For example, an abrasive wheel may besprayed with copper, brass or other suitable material in a thin coating.If desired this coating may be thickened by electrodeposition of suchmetals as copper, nickel, chromium, etc., the strength of which can befurther increased by annealing or .burnishing or both.

The material is applied by means of a metalspraying gun. Metals whichcan be obtained in wire form and which can be readily melted by means ofan oxyacetylene flame are used. The molten metal is driven at such apressure into the pores of the abrasive wheel that it forms a veryfirmly adhering coat. Suchcoatings strengthen the wheels and make itpossible to run them at increased speed, the increase in speed greatlydepending, as would be expected, on the metal used, its thickness, etc.

A sufficient coating may be applied in about five minutes on each faceof the abrasive wheel. Care is exercised that the least possible heatshock is given to the abrasive material. In fact it is better to warmthe wheel up slowly before spraying and cool slowly afterwards.

In Fig. 1 a metal reenforcement is shown covering part of the lateralsurface of an abrasive wheel. The portion 4 of the lateral surface ofthe abrasive wheel is shown with the metal reenforcement removed. Theabrasive wheel is shown as mounted on a shaft 5 with the aid of a leadbushing 8.

As the wheel wears down it may be necessary to remove a portion of thelateral reenforcement. This may be done by means of a lathe tool. In

some cases, however, this may not be necessary,

especially if thereenforcement does not extend an appreciablethicknessoutside of the abrasive wheel, but is largely confined to themetal which has penetrated the poresof the wheel.

While I have'described certain metallic materials for use in depositingmetal reenforcements, other materials, such as chromium or iron, may beapplied by suitable combinations of spraying and electrodeposition.

Among the advantages of my method, as above described, may be noted:

1. The reenforcement may be removed by a tool while the abrasive wheelis in operation.

2. The reenforcement. may be automatically removed in the process ofoperation of the wheel without the use of a dressing tool.

3. The sprayed metal reenforcement can be applied in a very short timeas compared with the amount of time required to apply cementingmaterials.

I claim:

1. As a new article of manufacture a unitary abrasive wheel having alateral reenforcement rigidly rooted in a side of the wheel, saidreenforcement consisting of metal which fills the pores .of the wheeladjacent the lateral surface and extends over said surface, and whichwears away in the ordinary process. of peripheral grinding by reason ofthe integral connection of the metal with the side of thewheel.

2. A method of laterally reenforcing a unitary abrasive wheel whichcomprises depositing metal in the pores adjacent a lateral surface andon the lateral surface to form a continuous layer of metal rooted in theabrasive.

3. The step in the method of providing lateral reenforcements forunitary abrasive wheels used for peripheral grinding, which stepcomprises spraying one or both sides of the unitary wheel with initiallymolten metal driven under pressure into the superficial pores, andbuilding up the lateral reenforcement by further spraying.

4. The steps in the method of providing lateral I reenforcement forunitary abrasive wheels used for peripheral grinding, which stepscomprise warming the unitary abrasive wheel slowly, spraying one or bothsides of the wheel with initially molten metal driven under pressureinto the superficial pores, building up the lateral reenforcement byfurther spraying, and slowly cooling the wheel.

5. The steps in the method ofproviding lateral reenforcement's forunitary abrasive wheels used for peripheral grinding, which stepscomprise spraying one or both sides of the unitary wheel with finelydivided metal and thickening the deposit b y electrodeposition of metalon the sprayed coating.

6. The method of providing lateral reenforcements for unitary abrasivewheels used for peripheral grinding, which method comprises spraying oneor both sides of the unitary wheel with finely divided metal, thickeningthe deposit by electrodeposition of metal on the sprayed coating,

and annealing the coating.

7. A unitary abrasive wheel having a lateral reenforcement for one orboth sides of the wheel, said reenforcement comprising a layer ofv metalrooted in the superficial pores of the reenforced surface by sprayingmolten metal against the abrasive surface, and an additional layer ofmetal electro-chemicall'y deposited on the sprayed coat- 8. A unitaryabrasive wheel including a porous body of bonded abrasive grain and alateral reenforcement in adherent contact with a side surface of thebody of the wheel, said reenforcement comprising a layer of metal driveninto the pores of said body so as to wet or give the effect of wettingthe surface thereof.

FRANK J. TONE.

